Method for indenting tubes



March 11, 1958 H. P. BROWN ET AL METHOD FOR INDENTING TUBES 5 Sheets-Sheet 1 Filed July 26, 1954 S m m 8 m m ms r m w: 31 .1 NE m mm" H WNM E v2 a. v HHHH l uhhl v m2 H mm. we C o: v on. U mm m M 1 h NN NN HOLLIS P.BROWN B2 WALTER Rwy y $4 ATTORNEYS March 11, 1958 H. P. BROWN ET AL 2,825,962

7 METHOD FOR INDENTINQ TUBES Filed July 26, 1954 5 Sheets-Sheet 2 ow. lwQ V s V m a a u v u n N m2. \JQE a mmm m. M? m Dn N9. N9 R on. mm 0A w 1 N\ I m f w? o. N

ow om mm ow March 11, 1958 H. P. BROWN ET AL 2,825,962

METHOD FOR INDENTING TUBES Filed July 26, 1954 5 Sheets-Sheet 4 l a I l l l 1 I I l i E' i r l o l I (D l l ul l l 0 I Q I I l l I I \w I N I J l x L I] I l: g: i 1 9 LIL L I I l 1' l l INVENTORS HOLLIS P. BROWN W BY WALTER R. RZKLI Z ATTORNEYS of etlat hing ball mhe indentat ons ereeivene shap in :tr nsyer e here see t on s ch tha the all ay t ly elong te tcatin th tub lar member amen. ar yiv with espec Q United States Patent Ofiice The-presen inven i n .relateste m hod forindentin tubes, n The: inv ntion his particular y xapp ica le.te the p ogiuetienmof u ularc rake pn ls eds ef thevtypemdisclosed .in prioncqpending application of Qhar eSQS- McCarthy, Serial No. 349,855. s

As m rerfu y .sh wn in th pr r.r open insl ppliea lions: the brak -pull rod-isformeddtubular stock having her sreceiving .i 1 e a icms f rmed ,;in a ignments lonew ,one;sider,thereof. ,Ihese indentationsare (designed 1,0 ,cpoperatewi h spri g pressed balls serving asl t h m mnberisin eninnetionrwith the in entati ns of. the undre tln erder to facil tate outward m vement of the n e to bralseapplying position, the hallreceiving indentations; are elonga ed in av dire tion.longi d a yni the tubeend are relatively deeper at one end than at the Qther, ,mfl'lfle deeper endsofhthe inden ations include generel yfiphe l surt eeme itens.engagea le hro gheutesub antiale e icamrnensoutwerdly of the all. receiv ng. indentatiens by JrotatiOnQf the p lredaboutits a i n of a novel methed ,for r nn ng the hallrre e ing .11 met -.1

tions in the tubular brake pull 110d,

i It dean ehieetof the .presentsi en en to vn mzi lmethe .Qf: ie minglanbralse .pu rm hhavin in en i n s l enesln e es Roi n ematieni f rmingle em nt di p se rimpnrallelismi saith the axis of. the tuhn an m m er a on a path having radial and axial components withqjrespect to he axisiof the :tubnl rwmemhercthe hy rimm ng-e inde tations having bstemielly jer ete hdepth atqn i; ndthaniat h nther;

his arurth r .Q i ct f h ,presentanvemion teupr vid ta .metho lmi .pro.ducing indented null, reds .deseribe in .the precedin pa a raph .whichginelru les. .the ep of 1 nvathtoiuadvanceof theiornfinglel. a rslotrin on endet th tnbu a mm mh a l eeat ng I shasfnrther. objec of the p e t. .inven i n-tq. pr

vid fit-110161; ,m thqdnof form ng entedetn ular imemb fi which. cQmpr-ises vlcl lt i l gfi tubular men bet on ia-suppert been, ela Me y-moving a pairief eppese ie path ofuadvance ofi tlrerforming elements-beingvlocatedrzin {a plane radial -of :the tubular Qmemberi-and extending :in

"Other objects; and --features-'-of the invention will 'ibecome---appa rent as ;the"description proceeds, ;espeeially when talren'in conjunction with the accompanying; draw- ;"iflESryvhereiu: :1. v

such plane atan oblique angle to the axis of thetubular memberi- 2,825,962 Patented Mar. 11, 1958 5 Figurejnisha transverse ,sectionpf the .ass,embled die andrn nehv head ta enin thehp an c elf the line Beg-3, Eigure...1(..

F u 4 a-pla view o v h vPu h he d.

F gured ,issan enlarged sectionalview .on the line .575, liigure. ,1.

.Eigvureme is, a detailed elevational 1 .view ...0,.f the .work lifter.

F gu e .7r.is a side .e'levatiena'l v yi wnof ua zforminstel m at-n- Figure 8 is a front elevational viewnof theim'ming elementeeenmin igure '7- .F g re..9 is. assomewsha di g amm ti .sec ional. v e .th ensh edifi dmferm. of die 'andlfe m ng elementt emlb n tion; .1 F gure s,aliragmentary: e at nel view o an 5 1 flentesintubiil rmm mber .a pr duee by t presen ;i.n-

vent p i-.,,

E gu e:.1.. s r't etn ta y.seetien' n the l e 1, -.1 Figure l JR e ringtirst eli gur sm and 1.1, the p sen en- ,t.. on.... e.1 es. te ie eduen -f pparatus. e gn dn ins vi den ed-i esaus fui ie .QKQIQPRAS br e .null reds-c WI f gures. .10 endll a eeti n re such i e ted tu e is i lus re-t d 1. v n bell re v ng vipee sets' 1.2 in ented therein ml ese rpeekets are el nga ed longitudinally .'.of th ube as. lu rat i uE gure l0, and be "illust ate i .fi u eslfl a at gradua y n r s'in it pth tewerd one end- A. h se p l tsw l q p rate with ilat h ng. hall in ca ed. at; 1. t e ba s be gspring nress di t e ese 35 .ment ith th t be en -h a ain t 'lo git inelim x inent- L1 the r a n h p lust a ed ini i gure 12 ,'i ,will be appa e h h ibel s a e eii etivet re ain-th tubul rime b r. es ne move en Winnie ireet en t -le t: @O t e ether a d, orces epp ee' n'dingit m ve t tu ular member 0 t th r ht'willt a e .t effectiof camrning'the balls 14 upwardly; In the same manner, wthe pockets 12 have a radius o f curvature at their pointyof greatest Width somewhat greater t han t he radiusjof curvature of the balls 14 so that theflballs may also be Qammed outwardly from the indentation or recess by rotation ,of the tubular memher; I v

Referring. now to Figures l-fi there is illustrated a preferred form ,of the apparatus ,for practicingf the nqvel method'of indenting the tubularmembers 1 0. jAsseenjn these figures, the apparatuscomprisesadie20having up- 'viiardly extending posts '22 adapted to be received within bushingsg 24 carried by the punch o r forming head 26 .il-

lustrated in Figure 4,

As best seen in Figures 3 ,and 5 the v die 2,!) comprises alower supporting plate,28 to which is fixedly mounted an elongated jaw member'30, this memberbeingholted or otherwise ,secured to the .plate 28 as indica'tedj'at 32 and abutting against an elongated members seated in a recess Qrmed in the upper surface of the plate 28. Slidably'mounted on a bearing plate 36 recessed in the uppersurface of the plate 28 is a movable j aw 3 ;the movable jaw 3,8 having connected thereto threadedjrdds .40 each of whichhas a springabutmentwasherflz locatedfiadjac'entits outer end and retained Lin'position by a lock nut set illustrated at 44. Bolted or otherwise secured to the upper surface of the die .p1ate 28 is an elongated block 46 having spring receiving recess es 48 therein .which receive compression springs 50. he compression springs 50 bear against thespring abutment washer 42 and bias the movable jawy 38 to the right as seen 0 inFigureJ. The bloclr46 bearsagainst a locator strip 52 recessed in the upper surface of the tlieplate 28. j

The stationary jaw 30 and the movable jaw 38 are provided with confronting recesses 54 in which are slidably mounted guide pins 56 urged outwardly of the recesses by compression springs 58. The pins 56 are provided with elongated slots 60 receiving the reduced ends of set screws 61 retaining the pins in the recesses and permitting limited longitudinal movement thereof.

Secured to the underside of the head plate 100 are cam blocks 62 having an inclined cam surface 63 adapted to cooperate with a correspondingly inclined camming surface 64 formed on the movable jaw 38. The rods 40 pass through elongated openings 65 in the cam blocks 62. The arrangement is such that upon downward movement of the head 26 cam surface 63 engages cam surface 64 and earns movable jaw 38 to the left as seen in Figure 3, thereby clamping the tubular member firmly in position prior to engagement therewith of the forming elements 102.

The die plate 28 is provided adjacent one end with a 9 block 68 which is bolted or otherwise secured thereto as indicated in Figure 5. The block 68 is located adjacent an elongated locator strip 70 mounted in an elongated recess forrned in the upper surface of the locator plate 28. Outwardly of the block 68, as best illustrated in Figure 2, is a smaller block 72. The blocks 68 and 72 have aligned openings 74 and 76 therein through which extends a longitudinally slidable locator element 78. The openings 74 and 76 are transversely elongated as best illustrated in Figure 5, to permit transverse rocking movement of the locator element 78. The locator element 78 is provided with a plurality of pin receiving openings 80, a selected one of which receives a pivot pin 82, the lower end of the pin being received in a pin receiving opening 84 in the block 72. The inner end of the locator element 78 is tubular and receives a rod 86, the rod including a transverse pin 88 the ends of which extend into aligned elongated slots 90 formed in the tubular portion of the locator element 78. At its inner end the rod 86 is provided with a blade 92 and a spherically formed button portion 94. The tubular member 10 is provided with a slot at the left hand end as illustrated in Figure 2, and the blade 92 enters into the slot and the button 94 enters into the end of the tube, thus serving to locate the end of the tube. The rod 86 is urged outwardly of the tubular portion of the locator element by a compression spring 96 so that thedevice urges the tubular member to the right against an abutment surface located at the opposite side of the die. The purpose of the blade 92 is to insure proper angular relationship between the slot at the end of the tube and the aligned row of indentations formed therein by the apparatus.

Associated with the die 20 is the punch or forming head 26 which comprises a plate 100 mounted for vertical guided movement toward and away from the die 20 by the pins 22 and the bushings 24 previously described.

' An assembly of forming elements 102 are mounted in an underlie downwardly facing shoulders 114 at the sides of the elongated strip 104. The underside of the strip 1.04

is provided with an elongated recess 116 adapted to receive an assembly of forming elements 102, these elements being rigidly clamped in position therein by a wedge strip 118 which engages the sides of the forming elements 102. The assembly of forming elements 102 is further positioned by a wedge block 120 engaging the inclined strip or block 104. The ways previously described allow longitudinal movement of the block or strip 104. As best seen in Figure 2, one end of the block 104 is provided with an inclined or beveled surface 122. The adjacent surface of the block 64, carried by the die plate 28, is correspondingly beveled and the two beveled surfaces operate as a cam to force the block or strip 104 to the right as seen in Figure 2 upon downward movement of the plate 100. In order to retain the longitudinally slidable block or strip 104 in proper position to be actuated by the camrned surfaces just referred to, a block 124 is rigidly secured to the underside of the head plate and is provided with a pair of spring receiving recesses 126, as best illustrated in Figure 4, compression springs 128 being received in these recesses and bearing against the right hand end of the block or strip 104. Forming elements 102 are alternated with spacers 103, and the tube is slotted axially between successive operations.

From the foregoing construction it will be apparent that downward movement of the head plate 100 results in a shifting movement of the block or strip 104 together with the forming elements 102 to the right. As a result of this the forming elements 102 are given a move ment relative to the tubular member 10 along a path having substantial radial and axial components with respect to the axis of the tube. In the illustrated embodiment of the invention the inclined surface 122 and the corresponding surface of the block 64 extend at an angle of 30 degrees to the axis of the tube and thereby the forming elements are moved into forming engagement with the tube along a path having equal radial and axial components.

The right hand end of the tubular member 10 engages a ground locating surface on an adjustable stop block 130 having locating surfaces 132, 134, 136, 138 and 140. The block 130 is adjustable transversely of the die plate 28, an elongated slot 142 and clamping bolt 144 being provided for this purpose. The block is accurately located in position against a locating strip 146 received in an elongated recess 148 machined in the upper surface of the plate 28.

In order to lift the completed tubular member 10 from the die following the indenting operation, there is provided a lifter blade 150 the inner end of which underlies the tubular member 10. The blade 150 is mounted in a block 152 bolted or otherwise secured to the upper surface of the plate 128 and is pivoted thereat by a pivot pin 154.

With the foregoing apparatus described, the operation will be apparent but will be briefly reviewed. With the head 26 elevated a tubular member is positioned between the jaws 30 and 38 which at this time will be slightly separated. The tubular member is retained in accurately located position between the jaws by engagement with the spring pressed plungers or pins 56, the inner ends of which are cylindrically recessed as best illustrated in Figure 3. At the same time the tubular member 10 is positioned with a slot at the left hand end thereof as viewed in Figure 2, the slot receiving a portion of the fiat blade 92. The left hand end of the tubular member also receives the spherical locating button 94 and the rod 86, urged to the right by the spring 96, presses the right hand end of the tubular member 10 against the appropriate one of the locating surfaces 132, 134, 136, 138 or 140, according to adjustment of the locator block 130. Downward movement of the head initially closes the movable jaw 38 on the stationary jaw 30, this movement being accompanied by a transverse shifting of the tubular member 10 which during this movement is maintained between the jaws by simultaneous yielding of the surface at one end of the recess 116 which receives the forming elements 102. By this construction the forming elements are rigidly locked in position in the elongated .asaneea tudinalslidingn ovement .of, theblochor strip 194.,as a

result-g. of the camming. en agement of. the {surface 122 .tt'hereof'and the correspon ing "beveled surface; progi'ded on theistationaryblock 64, 'this""'movement .QPerating against compression "springs L28; Accordingly, the form- "with 'respect to the axis' of the tube. As a result of this relative motion .of the lower forming .portionsnf the ele-.-

merits 102; they are progressively depressed downwardly and axially toproduceelongated indentations in the upper surface of thetubeextending lQngitudinally thereof, the portions of each indentation at. .the-righti'hand ientittheneof -as :vieWed-.-in:.Figure, 2, being deepernhan portions :Ihereoftoward theleft.

' When thehead is raised the indented tubularsmemher 10 is. freed from its support by depressingithe eaten-end; of the lifter.;150 downwardly, thus swinging the ilifitersabout its pivot axis 154 and raising its inner end to elevate nao the indented tube.

In order to keep the tube from collapsing, every other indent punch is left out. After the first stroke the end stop 130 and locator element 78 will be shifted to the right an amount equal to the required spacing between adjacent indentations. A second stroke of the press will complete the indentation of the pull rod.

Details of the forming elements 102 are best seen in Figures 7 and 8, it being observed that these elements have laterally extending flanges 156 adapted to seat in a locating groove at one side of the recess 116 as best illustrated in Figure 3. The lower portion of each locating element includes an inclined bottom surface portion 158 which may extend upwardly at an acute angle, and in a practical embodiment of the present invention this angle is approximately degrees. Vertical sections through the lower surface 158 of the forming elements are cylindrical and of constant radius, the radius of curvature being appreciably greater than the radius of curvature of the latching balls for which the forming elements produce cooperating indentations. The lower end portion 160 of the forming elements may be generally spherically formed to the right of the lowest point thereof as seen in Figure 7, this spherical surface having a radius of curvature approximately equal to that of the balls for which the construction is designed.

Referring now to Figure 9 there is illustrated more or less diagrammatically a modified form of apparatus for carrying out the method disclosed herein. In this case a die plate 170 is provided with a support block 172 adapted to support the tubular member 10 thereon. Vertically movable above the die plate 170 is a head plate 174 having a block 176 carried thereby provided with a multiplicity of forming elements 178 which may have end portions identical with those of the forming elements 102 previously described. The block 176 is arranged to carry the forming elements 178 in staggered alignment as illustrated in the figure. The support block 172 is arranged to carry the tubular member 10 with its axis disposed at an oblique angle to the horizontal, and in the illustrated embodiment of the invention the tube is supported at an angle of 45 degrees. Accordingly, the relative movement between the forming elements 178 during the forming action thereof with respect to the tubular member 10 is along a path having substantial radial and axial components with respect to the direction of the axis of the tubular member, and as illustrated the radial and axial components are equal. By obvious design change, the path of advance of the forming elements may be at an angle of 30 degrees to the tube axis, thus giving the same action as the apparatus of Figures l-3.

While the two embodiments of the mechanism previously described disclose relative movement between the tubular member and the forming elements along paths making angles of approximately 30 and 45 degrees re ,spec tively with respect to the axis of the .tubulanmember,

this'jpath, may be varied. somewhat. Also, as suggested by the dotted :line position of a single forming element designated .180" in Figure-'9, thefornliing elements might be inclined from the vertical in the "apparatus; disclosed in Figure 9 so long as the inclination=thereof does1not exceedthje slope-of the bottom surface portion-158 or in other i:words,"30 degrees :in the particularform-illus- 'trated.*; in "like manner, instead of moving-vertically downward as iliustrated in"Figure 9-, ;,the;forming elements couldrnove downwardlyand to the left at anyapprppr'iate an le..

it" thed'eeper end-ofi the indentation, the rounded end of the forming portion acts more nearly perpendicular *to engaging sm'facesat "the deeper ends o'f the indentations. So ,l'ong as thefioperat ionis carried out in this" way- 'iriis found 'thatbi, inch tubular: stock having a wall thickness of approximately inches' maybe indented-40' a' depth of approximately 5 inches so as to produce a satisfactory indented tubular pull rod for automobile brakes.

The drawings and the foregoing specification constitute a description of the improved method and apparatus for indenting tubes in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What we claim as our invention is:

l. The method of providing a tubular brake pull rod with a series of axially aligned indentations at one side only thereof which comprises supporting a length of tubular stock along the bottom and opposite sides, and moving an aligned series of forming elements into forming engagement with the stock along a path occupying a plane radial of the stock and in a direction oblique to the axis of the stock and having substantial radial and axial components with respect to the axis of the stock, thereby forming indentations in the ,stock which are elongated axially of the stock and relatively deeper at the end thereof toward which the forming elements move.

2. The method of providing a tubular brake pull rod with a series of axially aligned indentations at one side only thereof which comprises supporting a length of tubular stock along the bottom and opposite sides, and moving an aligned series of forming elements into forming engagement with the stock along a path having uuiform and substantial radial and axial components relative to the axis of the stock, thereby forming in the stock indentations which are elongated axially of the stock and relatively deeper at the end thereof toward which the axial component of motion causes the forming elements to advance.

3. The method as defined in claim 2 in which the path of advance is at an angle to the axis of the tube equal to about 30-45 degrees.

4. The method of making an indented tubular brake pull rod which comprises supporting a length of tubular stock along the bottom and opposite sides, locating the tubular stock in rotation by inserting a locating key in a slot in one end of the stock, and moving an aligned series of forming elements into forming engagement with the stock along a path occupying a plane radial of the stock and in a direction oblique to the axis of the stock, thereby forming indentations in the stock which are elongated axially of the stock and relatively deeper at the end thereof toward which the forming elements move.

5. The method of indenting tubes which comprises providing a forming element having an elongated forming surface adjacent a tube, the forming surface having a rounded end portion and a portion inclined outwardly from the tube extending from the rounded end portion to the other end of the elongated forming surface, and relatively feeding the forming element into the tube along aaaaeea I a path having both radial and axial components relative surface moves radially into the tube material and axially thereof in advance of the remaining inclined portion thereof, and enlarging the indentation in the tube laterally and axially from the point of initial contact of the rounded end portion of the elongated forming surface of the forming element in a direction opposite to the axial component of the path of relative movement between the tube and forming element.

6. The method of indenting tubes which comprises providing a forming element adjacent the side of a tube, the forming element having a forming portion elongated axially of the tube, the forming surface having a rounded end portion, the remainder of said forming surface being inclined outwardly from the tube, effecting relative approach between the tube and element to initiate indentation of the tube with the rounded end portion of the forming surface of the forming element, forcing said element to move relatively into' the tube along a path occupy ing a plane radial of the tube and making an acute angle to its axis, and extending the indentation in the tube both laterally and axially of the tube in both directions by maintaining the angle between the path of relative advance of the tube and element and the axis of the tube larger than the angle of inclination between the inclined surface of the forming element and the axis of the tube.

References Cited in the file of this patent UNITED STATES PATENTS Rainforth Nov. 3, 1903 Huyett Feb. 13, 

